1. Field of the Invention
The present invention relates to a method and apparatus for treating a site contaminated with a hazardous substance. More particularly, the invention relates to a method and apparatus for remediating soil and groundwater in a site contaminated with a hazardous substance.
2. Description of the Prior Art
Worldwide, the storage and transportation of hazardous substances requires countless tanks and pipelines. Substances typically processed in these facilities include petroleum distillates, industrial solvents, and industrial wastes. Due to the dangers presented by storing and transporting concentrated solutions of these materials, engineers and government agencies conduct extensive research and development to insure the tanks and pipelines used will effectively and safely contain these materials. Weathering and unforseen engineering limitations, however, often cause the facilities to fail, resulting in the release of chemicals into the environment.
The failure of storage tanks and pipelines impacts on the physical and economic vitality of the contaminated area. The release of concentrated chemical solutions typically causes extensive damage to the local ecosystem by contaminating or killing indigenous plant and animal life. More remote ecosystems may be affected if the contamination migrates from the site by entering the local groundwater flow. Further, local laws often require that contaminated areas be remediated, and certified as such, prior to sale or rental. These laws often result in land being left fallow for years or decades. In extreme cases, the inability to remediate contaminated sites renders industrial or residential areas uninhabitable, forcing owners and employees to evacuate the area.
Several methods are currently employed to remediate sites contaminated with hazardous substances. Unfortunately, available methodologies are often limited by soil conditions which, among other things, effect the rate of migration of hazardous contaminants. Also impacting on the usage of available remediation techniques is the size and configuration of the contamination plume. At present, a common practice for the remediation of contaminated sites consists of locating a pumping system at or near the center of the plume. Contaminated groundwater is then pumped to the surface at a rate sufficient to create a cone of depression. The cone of depression causes floating contaminant to flow into the pumping well where the separation of contaminant from the groundwater can be accomplished using, for example, slow moving vertical flat, or round, belts made of oleophilic and hydrophilic materials. Although effective for some applications, the physical size of these systems, and their power requirements, can render them inappropriate.
A need has arisen for an improved method and apparatus for the remediation of sites contaminated with hazardous substances.